AN Loft Splines not observing vertex hooks
Unfortunately, this is not possible in Animation Nodes. Jacques Luke (AN Developer) said the following about this particular issue:


  Blender does not (to my knowledge) allow scripts to get the result of curve modifiers in a way that is suitable for AN. The only possible way to see atm is that AN makes a copy of the curve object, applies all modifiers, hopes that the result is only a single spline, loads that spline into AN and removes the copied spline. This would have to happen on every recalculation. While the performance might be good enough when the spline is small, there are other problems when using this approach. Specifically it requires AN to use certain operators that should not be used during rendering.


What you can do however, is implement the hook modifier inside animation Nodes instead. Below, I will explain a potential way to do this.

Animation Nodes Hooks

First, I will rename all the hooks, where the name is "Hook.n" where n is the index of the spline point it should control. Then I will loop over the spline points of the spline, check if an object exist by the name "Hook.n" where n is the index, If I find an object by that name, I append the hook location, otherwise, I append the spline point location. What we end up with is the new locations of the spline points:

 

And now we can safely regenerate the spline with the new locations:



Hooks are however defined as an offset from their initial location, the same can be done in Animation Nodes using ID Keys, but I will leave that to you.

Animation Nodes Issues

StackExchange is no place to report Animation Nodes bugs, Github issues in the AN repository is the place to share bugs in:

https://github.com/JacquesLucke/animation_nodes/issues/new